Epidermolysis bullosa simplex (EBS)
is usually inherited as an autosomal
dominant disease due to monoallelic
gain-of-function mutations in KRT5 or
KRT14. Although autosomal recessive
forms of EBS have been associated
with mutations in at least 10 genes,
recessive EBS due to homozygous
biallelic KRT5 has not been previously
reported; it has been hypothesized that
it would result in prenatal lethality. Our
findings now identify biallelic KRT5
mutations with a phenotypic spectrum
varying from mild, localized and
generalized to lethal, expanding the
genotypic profile of autosomal
recessive EBS.

Homozygous Biallelic KRT5 Mutations in Epidermolysis Bullosa Simplex, Including a Complete Human Keratin 5 “Knock-Out”, in Families with Extensive Consanguinity